Question

Вариант 2 1. Выполните умножение а) 2/3 * 5/7 б) 4/11 * 5/8 2) Выполните действие 3/4 * (5/9 - 2/3) 3) Найдите значение выражения: (3/13 + 4/7) * 91 . 3) Бригада выполнила за первый день работы 30% плана, за второй день - 1/5 от оставшейся части плана, за третий день - всю оставшуюся часть плана. Какую часть плана выполнила бригада за третий день? 5) Найдите значение выражения: 3 2/5 * 1 4/7 + 2 3/7 * 3 2/5 - 13 3/5 * 1/2 ПОМОГИТЕ ПОЖАЛУЙСТА! ЭТО ДОМАШНЯЯ КОНТРОЛЬНАЯ 6 КЛАССА!

Answer 1

Это только 1 2 3. как 4 и 5 не знаю

Answer 2

1. Выполните умножение:

a) 2/3 * 5/7 b) 4/11 * 5/8

To multiply fractions, you simply multiply the numerators together and the denominators together. Let's solve these:

a) 2/3 * 5/7 = (2 * 5) / (3 * 7) = 10/21

b) 4/11 * 5/8 = (4 * 5) / (11 * 8) = 20/88, which can be simplified to 5/22.

So, the answers are: a) 2/3 * 5/7 = 10/21 b) 4/11 * 5/8 = 5/22

2. Выполните действие 3/4 * (5/9 - 2/3)

To solve this expression, we need to simplify the expression inside the parentheses first:

5/9 - 2/3 = (5/9) - (6/9) = -1/9

Now, we can multiply this result by 3/4:

3/4 * (-1/9) = (3 * -1) / (4 * 9) = -3/36, which can be simplified to -1/12.

So, the answer is: 3/4 * (5/9 - 2/3) = -1/12

3. Найдите значение выражения: (3/13 + 4/7) * 91

To solve this expression, we need to simplify the addition inside the parentheses first:

3/13 + 4/7 = (3 * 7 + 4 * 13) / (13 * 7) = (21 + 52) / 91 = 73/91

Now, we can multiply this result by 91:

(73/91) * 91 = 73/1 = 73

So, the answer is: (3/13 + 4/7) * 91 = 73

4. Бригада выполнила за первый день работы 30% плана, за второй день - 1/5 от оставшейся части плана, за третий день - всю оставшуюся часть плана. Какую часть плана выполнила бригада за третий день?

Let's break down the information given step by step:

- The brigade completed 30% of the plan on the first day. - On the second day, they completed 1/5 of the remaining part of the plan. - On the third day, they completed the remaining part of the plan.

To find out what part of the plan the brigade completed on the third day, we need to calculate the remaining part of the plan after the first and second days.

Let's assume the total plan is represented by 100%.

- On the first day, they completed 30% of the plan, so 70% of the plan remains. - On the second day, they completed 1/5 of the remaining 70%, which is (1/5) * (70/100) = 14/100 = 14% of the plan. This means 56% of the plan remains. - On the third day, they completed the remaining 56% of the plan.

So, the brigade completed 56% of the plan on the third day.

5. Найдите значение выражения: 3 2/5 * 1 4/7 + 2 3/7 * 3 2/5 - 13 3/5 * 1/2

To solve this expression, we need to convert the mixed numbers into improper fractions and then perform the operations.

Let's convert the mixed numbers into improper fractions:

3 2/5 = (3 * 5 + 2) / 5 = 17/5 1 4/7 = (1 * 7 + 4) / 7 = 11/7 2 3/7 = (2 * 7 + 3) / 7 = 17/7 3 2/5 = (3 * 5 + 2) / 5 = 17/5 13 3/5 = (13 * 5 + 3) / 5 = 68/5

Now, let's perform the operations:

17/5 * 11/7 + 17/7 * 17/5 - 68/5 * 1/2

To add or subtract fractions, we need to have a common denominator. In this case, the common denominator is 35.

(17/5 * 11/7) = (17 * 11) / (5 * 7) = 187/35 (17/7 * 17/5) = (17 * 17) / (7 * 5) = 289/35 (68/5 * 1/2) = (68 * 1) / (5 * 2) = 34/5

Now, let's calculate the final expression:

187/35 + 289/35 - 34/5

To add or subtract fractions, we need to have a common denominator. In this case, the common denominator is 35.

(187/35 + 289/35 - 34/5) = (187 + 289 - 238) / 35 = 238/35

The fraction 238/35 can be simplified to 34/5.

So, the answer is: 3 2/5 * 1 4/7 + 2 3/7 * 3 2/5 - 13 3/5 * 1/2 = 34/5